Purpose: The aim of this study was to sample biofilms in different food companies and to characterize the microbial population and matrix components of these presumptive biofilms.
Methods: Surfaces in eight food companies were sampled after cleaning and disinfection. Different microbiological enumerations were performed on the samples and the dominant bacteria were identified using (GTG)5 clustering, followed by 16S rRNA gene sequencing. Also, the biofilm matrix components proteins, carbohydrates, and uronic acids were determined. The possibility of the collected dominant bacteria to form a biofilm, under lab conditions, was evaluated in microtiter plates.
Results: The proportion of microbiologically contaminated surfaces varied from 0-64% across the different food companies, with values varying from 0.00 to 7.23 log CFU/100cm². For 0-33% of the sampled surfaces from the food companies, microorganisms were found in combination with biofilm matrix components. Identification of the collected isolates showed wide diversity; but, the most common identified species were Pseudomonas spp. (26.3%), Stenotrophomonas spp. (8.3%) and Microbacterium spp. (8.1%). Regarding the biofilm-forming properties, microorganisms with the strongest possibility to form biofilms were part of the Pseudomonas, Acinetobacter, and Stenotrophomonas families.
Significance: Detection and characterization of biofilms, in the concerned food companies, gave useful insights in the potential to cause food spoilage and foodborne infections; and offered a basis for the development of more efficient cleaning and disinfection procedures.